During the coming year we will attempt to develop a specific radioimmunoassay for thyroglobulin-anti-thyroglobulin complex using immune rabbit sera now available, perfect the immunoassay for free thyroglobulin for clinical use, study the reactivity to mitogens of lymphocytes obtained from Graves' patients before and after passage through histamine affinity columns (which remove a sub-population of T-lymphocytes), continue to study and treat patients with Graves' ophthalmopathy according to the established research protocol, and determine histocompatibility antigen and thyroid autoantibody frequency in members of a few selected families wherein thyroid disease is unusually common.